Patients 21 years of age and older with essential tremor may be eligible for this 10-day study. Candidates will be evaluated with a neurological examination, blood tests, urinalysis and electrocardiogram (EKG). Those enrolled will be admitted to the hospital for 4 days for 1-octanol administration and monitoring. On day 1, patients will have a medical history and physical examination. A catheter (a thin plastic tube) will be placed in a vein of the forearm for sampling blood. Patients will take one 1-octanol capsule (at one of seven doses) by mouth and will be monitored for tremors and drug side effects. Blood will be sampled periodically in the first 3 hours to determine 1-octanol blood levels. On days 2 and 3, patients will be monitored for additional side effects. On days 3 and 4, laboratory tests (blood and urine) will be done to evaluate liver and kidney function. On day 4, the catheter will be removed and the patient will be discharged from the hospital. A follow-up visit will be scheduled 1 week after discharge for a physical examination and blood, urine and EKG tests.